GM and Drain Plugs

[rpn453]

I changed the oil, coolant, and differential oil on my father's '97 Safari recently, and I noticed a pattern. As with my old Grand Am and my mother's Sunfire, there is no drain valve on the radiator, so I had to pull a hose and try to catch as much fluid as I could in the pan. I figure I caught about 6 liters and dumped 1 on the floor. To change the differential oil, I had to remove the cover, as there is also no drain plug on that. I noticed there is no drain on the transmission either, as it is with the Sunfire and was with the Grand Am. The lack of these drain plugs makes routine maintenance a lot more hassle than I think it should be.

Is this aversion to drain plugs mainly a GM thing, or have I just been lucky on the few other vehicles I've worked on? My Mazda3 has a radiator drain valve, like my old Pathfinder and the ex's MX-6. The MX-6 has a drain plug on the transmission (auto), and the Pathfinder has a drain plug on the differential. The Mazda3 and Pathfinder have drain plugs on the manual transmissions, of course.

Now for the comedic relief:
The coolant was the sludgiest coolant I've ever seen, yet he seemed annoyed with me when he found out I didn't save the coolant for him. He doesn't believe coolant goes bad, so he would have just used it again after letting the solid matter settle out. I refilled with the Prestone AM/AM he provided.

 

[SLCraig]

Weird!
My Saturn has a radiator drain plug, and a drain plug under my water pump... Also has a drain plug on my trans.

 

[robshelton]

I recently put a clutch in a 2004 Chevy Cavalier and there was no way to "Check" the fluid level in the transaxle. Had to drain and refill with a specified amount. Not really a big deal, but seemed so cheap...Of course it was a Cavalier...

 

[Fazzone]

Couldn't agree more! Don't get me wrong, I have only owned GM products and plan on keeping it that way, but that is one area that they could pay a little more attention to. I do have drain plugs on everything but the tranny and radiator, but the engine oil plug is in about the worst place. It is directly in front of the exhaust(you can just barely squeeze a rachet and socket in there) and dead center with the pipe, so not making a mess is next to impossible. Not sure what they were smoking when that design was come up with....

 

[Colt45ws]

I know the Montana, the Cavalier, and Saturn all have Radiator Drain plugs. Only the Saturn has a transmission drain, but it is the only Manual Trans vehicle.

 

[aquariuscsm]

Something I thought was cool that I`d never seen before.......my auto tranny 3000GT had a drain plug for the tranny. First car I`ve ever seen that had a drain plug for an auto tranny.

 

[Familyguy]

Originally Posted By: Onmo'Eegusee
I know the Montana, the Cavalier, and Saturn all have Radiator Drain plugs. Only the Saturn has a transmission drain, but it is the only Manual Trans vehicle.


Another thing I liked about the old Saturns was the external spin-on filter for the transmission. I wish more manufacturers would do that.

 

[defektes]

Odd my Sierra has a radiator drain valve, differential drain plug, and a transmission drain plug.

 

[JustinH]

The 03 sunfire doesn't have a radiator drain plug, it has this odd little plastic widget that requires a special GM tool to drain the radiator.

I tried to get it loose with a screwdriver, and started to strip the widget, and decided at that point to just drop the lower radiator hose and refill.

Funny, because my 03 saturn is a way better built car. It has a proper petcok, and many other things are built much better.

If you are removing a taillamp on the pontiac, you will see that instead of a regular metal nut, they used an aluminum nut that is about the thickness of a coin.

 

[Kruse]

As a work car, I'm currently driving a '98 3.1 Monte Carlo that was given to me. It needed new intake manifold gaskets, but the engine seems to be okay after I replaced them. The radiator in this car has a drain plug, but it's possible that it's been replaced by an aftermarket, as I'm not sure of the previous history.

 

[GMBoy]

I can do without the diff drain plug because I like to look inside and wipe it clean when changing the fluid and you don't do it often enough for it to be a big inconvenience. But I fully agree that the trans should have a plug. My old Jeep Cherokee had a plug on the trans and I love that because I could do a quick drain and refill at every other oil change or so and not get dirty or have to mess with the pan. Always had fresh trans fluid in there. As for the radiator petcocks - they usually drained too slow anyway and I always pulled the lower hose, but yeah it is nice to be able to catch it all in a pan.

 

[jcwit]

It's not just GM, got a Ford Escort that had no drain on the tranny, easy fix was to remove the pan and have an adapter welded on to accept a drain plug.

 

[mechtech2]

The sludgiest coolant that I have seen would not drain.

 

[NYEngineer]

My 98 Yukon had a rediator petcock, but it's brutally slow and in a terrible location.

My wife's 01 Saturn L300 has one as well.

Moroso makes an aluminum adapter that you install in a hose and it gives you a petcock pretty much wherever you can put it. I think they come in 1 1/4 and 1 1/2".

 

[thooks]

World of difference between a GM and a Honda.

Honda has drain plugs on the radiator, transmission, transfer case, rear end, etc.

All easily accessible and all make for easy maintenance.

I do remember there being a drain plug on the transmission and rear end of my last GM truck. But they said you better have a gorilla to get the tranny plug loose.

 

[rpn453]

Originally Posted By: mechtech2
The sludgiest coolant that I have seen would not drain.

I think most of the sludge was left over from the previous coolant, as this was the green stuff and it originally had Dex-Cool. The coolant I drained didn't look nearly as sludgy as the reservoir, rad cap, and radiator internals suggested it would. I don't know anything about this van's history, as he just recently bought it to replace his '92 Astro work van that is finally being written off after being hit a few times and vandalized.

 

[rpn453]

Originally Posted By: GMBoy
I can do without the diff drain plug because I like to look inside and wipe it clean when changing the fluid and you don't do it often enough for it to be a big inconvenience


In this case, it was good to get a look inside as the history is unknown and this is almost certainly the original fluid at 100k miles. The gears looked good, and I was able to confirm that it is a limited-slip. He wasn't sure, but suspected it was. I installed Lucas 75W-90 GL5, recommended for LSD.

 

[fdcg27]

So does my new Subaru.

 

[fdcg27]

So does my new Subaru.

 

[Scdevon]

Originally Posted By: thooks
World of difference between a GM and a Honda.



Not even in the same universe as each other.
High quality imports like Hondas are a breeze to work on. I respect that some poeple are domestic fans, but in my experience, many of them have never worked on imports side-by-side with domestics to see what a major PITA domestics are.

Just my opinion.